Apparatus for collecting drilling samples



Dec. 27, 1955 J. EDWARDS 2,728,553

APPARATUS FOR COLLECTING DRILLING SAMPLES Filed Sept. 27, 1954 Q 3/ IO 23 I FIG. 3.

F IG. 5.

JOHN EDWARDS INVENTOR.

A TTORNE Y United States. Patent APPARATUS FOR COLLECTING DRILLING AMPLES John Edwards, Midland, Tex. I Application September 27, 1954, Serial No. 458,611 4 Claims. (Cl. 2551.4)

This invention relates to the rotary method of drilling wells and has reference to apparatus for collecting formation samples during drilling operations. Samples so collected are used for logging purposes, i. e., making a record of the kinds of formation encountered at different depths. Such information is useful for many purposes, e. g., determining the presence of fiuids (oil, gas or water) at different depths, correlation with other logged wells for determining sub-surface structure, for determining the thickness of a pay zone, and information for completing a well. Heretofore, samples were collected by taking cuttings from the return circulation of the drilling fluid, or by stopping the drilling operation and taking cuttings from the bottom of the well by means of a wire line and a container on the lower end thereof. By reason of their weight and their tendency to either settle out or rise when suspended in the return drilling fluid, and by reason of the inaccurate means available for exactly determining the time required for the return flow to reach the earths surface, the collecting and the examining of cuttings from the return flow method is not entirely satisfactory. The collecting of cuttings by the wire line method, while accurate as to the depth from which they are taken, is also unsatisfactory because it is necessary to suspend the drilling operation while running the wire line.

An object of the invention is to collect samples from known depths without suspending drilling operations. Another object of the invention is to reduce the cost of drilling by obtaining good samples while drilling with a low viscosity drilling fluid. Another object of the invention is to collect groups of samples at a location near the drill-bit and separately containing each group of samples whereby the same is separate from other samples collected and unmixed with other earth particles sometimes present in the drilling fluid for various reasons, such as caving.

A particular object of the invention is to provide apparatus whereby the cost of drilling may be reduced. Specifically, the invention makes possible the use of inexpensive low viscosity drilling fluids since it is not necessary to suspend the cuttings in the return circulation.

These and other objects will become apparent from the following description and the accompanying drawing, wherein:

Figure l is a broken elevation and sectional view of an exemplary form of the invention in a well being drilled.

Figure 2 is an enlarged broken elevation and sectional view of a release mechanism for actuating the collecting rings.

Figure 3 is a broken elevation of the upper portion of the apparatus shown in Figure 2 and taken at a right angle with respect thereto.

Figure 4 is a transverse sectional view taken on line 4-4 of Figure 2, and

Figure 5 is an enlarged vertical broken section of the collector rings in their raised position.

The illustrated form of the invention includes a tubular body or mandrel 10 which is secured to the lower end of a drill stem, not shown, and has a rotary rock-bit 11 secured for operation on the lower end thereof. The bit 11 may be secured to the lower end of the mandrel 10 by suitable means, such as a split ring collar 12 and bolt 13. An axial opening 14 extends through the mandrel 10 and communicates with the drilling fluid port 15 extending through'the body of the bit 11. The upper portion of the mandrel 10 is provided with a cylindrical housing 16 therearound, and which housing is provided with numerous apertures 17 for equalizing pressure between the inside and outside thereof. The housing 16 is supported around the mandrel by means of ring plates 18 in its upper and lower ends, and which plates are detachably secured in place by means of set screws 19. Only the lower ring plate 18 is shown in the drawings since it is believed to be obvious that the upper ring plate would be installed in exactly the same manner adjacent the upper end of the mandrel 10.

Concave hollow ring collectors 20 are slidably mounted on the mandrel 10 between the ring plate 18 in the bottom of the housing 16 and the retaining collar 12 above the bit 11. The surface of the mandrel between the last referred to ring plate 18 and the bit 11 is provided with a flat surface longitudinally thereof and a longitudinal groove 22 is provided therein for slidably receiving a vertical traveling release bar 23. The lower inner'periphery of each collector ring 20 is chamfered, as at 24, and is engaged by a latch 25 pivotally mounted at its upper end Within the groove 22 and near the outer opposite edges thereof. As shown in Figure 5, each latch is held in a vertical position and engages its adjacent collector ring 20 until released by the upward movement of the travelling release bar 23.

As shown in Figures 1 and 2, the sides of the release bar 23 are provided with notches 26 which are spaced from each other at distances substantially equal to the thickness of each ring 20. Within the housing 16 there are pairs of weights 27 pivotally mounted on the mandrel 10 by means of supports 28 projecting from the latter and ears 29 on the lower outer surfaces of said weights. While the weights 27 may assume various configurations, the weights shown are downwardly and outwardly tapered on their outer surfaces and their inner surfaces are arcuate to conform with the cylindrical surface of the mandrel 10. The reason for this particular shape is to cause the same to normally assume relative contracted positions by gravity when not moved outwardly by centrifugal force. The housing 16 limits the outward movement of the weights 27, but it is pointed out that the respective pairs of weights 27 may have tension springs connected therebetween for resuming their contracted position after centrifugal action. The weights 27 are provided with depending and converging arms 30, and the arm of the lowermost pair of weights having depending pivoted dogs 31 on the lower end thereof. The dogs 31 are shaped to engage the notches 26 in the sides of the travelling release bar 23. Pawls 32 are mounted on the mandrel 10 at the sides of the groove 22 and are normally moved inwardly by springs 33 also mounted on the mandrel 10. The pairs of weights 27 operate in unison by means of connecting links 27a pivotally connecting the extending ends of the weight arms 30.

In operation, the referred to drill stem is rotated in the usual manner, and the drilling operation is carried out as in conventional rotary drilling operations. Initially, all of the collector rings 20 are in their raised position on the mandrel 10 and are held in place by the latches 25 and the travelling release bar 23. As the drilling operation takes place, drilling fluid is forced downwardly through the drill pipe, the mandrel 10 and the rock bit 11. The fluid then circulates upwardly carrying with it cuttings at least to. the vicinity of the collector rings 20. Since the present method does not require suspension of the cuttings in the drilling fluid all the way to the earths surface, a low viscosity fluid may be used; thus, the cuttings are free to settle into the collector rings 20 as the same are released. The release operation of each lower ring is accomplished by merely increasing the R. P. M. of the drilling operation at the depth where the sample is to be taken. The out- Ward movement of the weights 27 actuates the dogs 31 and thereby moves the release rod a distance equal to the thickness of one ring. As the lower end of the release rod moves upwardly from the adjacent latch 25, the latter is released and allows the lowermost collector ring to drop and rest on the collar 12. Each subsequent operation, i. e., increased R. P. M. of the drill stem, causes another ring 20 to drop, covering the last dropped ring and thereby sealing the cutting samples therein. As it is necessary to replace the bit 11 from time to time, the drill stem is withdrawn and the samples are removed from the rings 20. It is to be understood that the depth of the bit is known to the driller at all times, and by merely recording the speed-up operation for actuating the release mechanism, the depth of each sample may be tabulated when the rings 20 are brought to the earths surface.

The invention is not limited to the construction herein shown and described, but may be made in many ways within the scope of the appended claims.

What is claimed is:

1. Apparatus for collecting cuttings in a well, said apparatus comprising a'mandrel adapted to be connected in a length of drill pipe, concave collector rings slidably mounted on said mandrel, means supporting said rings in a raised position one above the other, means successively releasing the lower said ring, and means supporting the lowermost ring after the same is released.

2. Apparatus for collecting cuttings in a well, said apparatus comprising a mandrel adapted to be connected in a length of drill pipe, concave collector rings slidably mounted on said mandrel, means supporting said rings in a raised position, means including a vertically movable rod supported by said mandrel for successively releasing the lowermost said rings, centrifugally operated means raising said rod, and means supporting said rings one on the other on said mandrel after the rings are released.

3. Apparatus for collecting cuttings in a well as defined in claim 2, and wherein said centrifugally operated means actuating said rod includes notches therein, weights pivotally mounted on said mandrel, and dogs pivotally mounted. on said weights and arranged to engage said notches.

4. In combination with the apparatus defined in claim 3, the construction wherein said weights are arranged one above the other on said mandrel, and including links connecting said weights whereby the same operate in unison.

References Cited in the file of this patent UNITED STATES PATENTS 1,871,328 Kunz Aug. 9, 1932 1,955,166 Bannister Apr. 17, 1934 2,238,533 McClease Apr. 15, 1941 

